mbed-os/targets/TARGET_NUVOTON/TARGET_M2351/trng_api.cpp

143 lines
4.0 KiB
C++

/* mbed Microcontroller Library
* Copyright (c) 2017-2018 Nuvoton
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#if DEVICE_TRNG
#include "cmsis.h"
#include <limits.h>
#include "crypto-misc.h"
#include "hal/trng_api.h"
#include "platform/mbed_toolchain.h"
#include "platform/mbed_critical.h"
#include "platform/mbed_error.h"
#include "nu_modutil.h"
#include "hal_secure.h"
#include "partition_M2351.h"
#if defined(SCU_INIT_PNSSET5_VAL) && (SCU_INIT_PNSSET5_VAL & (1 << 25))
#error("We just support secure TRNG")
#endif
#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3L)
/* Module init definition: modname, clkidx, clksrc, clkdiv, rstidx, irqnum, misc */
static const struct nu_modinit_s trng_modinit = {TRNG_0, TRNG_MODULE, 0, 0, TRNG_RST, TRNG_IRQn, NULL};
/* TRNG init counter. TRNG is kept active as it is non-zero. */
static uint16_t trng_init_counter = 0U;
#endif
void trng_init(trng_t *obj)
{
trng_init_s(obj);
}
void trng_free(trng_t *obj)
{
trng_free_s(obj);
}
int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
{
uint32_t output_length_;
int32_t rc = trng_get_bytes_s(obj, output, (uint32_t) length, &output_length_);
if (output_length) {
*output_length = output_length_;
}
return rc;
}
#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
extern "C"
__NONSECURE_ENTRY
void trng_init_s(MBED_UNUSED void *obj)
{
core_util_critical_section_enter();
if (trng_init_counter == USHRT_MAX) {
core_util_critical_section_exit();
MBED_ERROR(MBED_MAKE_ERROR(MBED_MODULE_HAL, MBED_ERROR_CODE_OVERFLOW), \
"TRNG initialization counter would overflow");
}
++ trng_init_counter;
if (trng_init_counter == 1) {
/* Enable IP clock (secure version) */
CLK_EnableModuleClock_S(trng_modinit.clkidx);
/* Reset IP (secure version) */
SYS_ResetModule_S(trng_modinit.rsetidx);
TRNG_T *trng_base = (TRNG_T *) NU_MODBASE(trng_modinit.modname);
trng_base->ACT |= TRNG_ACT_ACT_Msk;
while (!(trng_base->CTL & TRNG_CTL_READY_Msk));
}
core_util_critical_section_exit();
}
extern "C"
__NONSECURE_ENTRY
void trng_free_s(MBED_UNUSED void *obj)
{
core_util_critical_section_enter();
if (trng_init_counter == 0) {
core_util_critical_section_exit();
MBED_ERROR(MBED_MAKE_ERROR(MBED_MODULE_HAL, MBED_ERROR_CODE_UNDERFLOW), \
"TRNG initialization counter would underflow");
}
-- trng_init_counter;
if (trng_init_counter == 0) {
TRNG_T *trng_base = (TRNG_T *) NU_MODBASE(trng_modinit.modname);
trng_base->ACT &= ~TRNG_ACT_ACT_Msk;
/* Disable IP clock (secure version) */
CLK_DisableModuleClock_S(trng_modinit.clkidx);
}
core_util_critical_section_exit();
}
extern "C"
__NONSECURE_ENTRY
int32_t trng_get_bytes_s(MBED_UNUSED void *obj, uint8_t *output, uint32_t length, uint32_t *output_length)
{
/* Check augument validity */
if (!output && length) {
return -1;
}
uint8_t *output_ind = output;
uint8_t *output_end = output + length;
TRNG_T *trng_base = (TRNG_T *) NU_MODBASE(trng_modinit.modname);
for (; output_ind != output_end; output_ind ++) {
trng_base->CTL |= TRNG_CTL_TRNGEN_Msk;
while (!(trng_base->CTL & TRNG_CTL_DVIF_Msk));
*output_ind = trng_base->DATA & 0xff;
}
if (output_length) {
*output_length = length;
}
return 0;
}
#endif
#endif